I've noticed a few shops now offering to pay customers to go online and give feedback about their shopping experience. Normally this is a competition entry so in practice the chances are a customer won't get anything for their time, but I found that Tescos is giving loyalty points if you're part of their clubcard scheme. They were worth £2.50 when I filled one out. Are there any other stores you know of doing this? It's normally printed on a receipt at the bottom: "Were you happy today please go to (URL) to let us know" or something like that.